Ångstrom-scale gold particles loaded with alendronate via alpha-lipoic acid alleviate bone loss in osteoporotic mice.

Osteoporosis is a highly prevalent metabolic disease characterized by low systemic bone mass and deterioration of bone microarchitecture, resulting in reduced bone strength and increased fracture risk. Current treatment options for osteoporosis are limited by factors such as efficacy, cost, availability, side effects, and acceptability to patients. Gold nanoparticles show promise as an emerging osteoporosis therapy due to their osteogenic effects and ability to allow therapeutic delivery but have inherent constraints, such as low specificity and the potential for heavy metal accumulation in the body. This study reports the synthesis of ultrasmall gold particles almost reaching the Ångstrom (Ång) dimension. The antioxidant alpha-lipoic acid (LA) is used as a dispersant and stabilizer to coat Ångstrom-scale gold particles (AuÅPs). Alendronate (AL), an amino-bisphosphonate commonly used in drug therapy for osteoporosis, is conjugated through LA to the surface of AuÅPs, allowing targeted delivery to bone and enhancing antiresorptive therapeutic effects. In this study, alendronate-loaded Ångstrom-scale gold particles (AuÅPs-AL) were used for the first time to promote osteogenesis and alleviate bone loss through regulation of the WNT signaling pathway, as shown through in vitro tests. The in vivo therapeutic effects of AuÅPs-AL were demonstrated in an established osteoporosis mouse model. The results of Micro-computed Tomography, histology, and tartrate-resistant acid phosphatase staining indicated that AuÅPs-AL significantly improved bone density and prevented bone loss, with no evidence of nanoparticle-associated toxicity. These findings suggest the possible future application of AuÅPs-AL in osteoporosis therapy and point to the potential of developing new approaches for treating metabolic bone diseases using Ångstrom-scale gold particles.

Multidimensional characteristics of musculoskeletal pain and risk of hip fractures among elderly adults: the first longitudinal evidence from CHARLS.

BACKGROUND: Hip fractures are a major public health concern among middle-aged and older adults. It is important to understand the associated risk factors to inform health policies and develop better prevention strategies. Musculoskeletal pain is a possible implicating factor, being associated with physical inactivity and risk of falls. However, the association between musculoskeletal pain and hip fractures has not been clearly investigated. METHODS: A nationally representative sample of the Chinese population was obtained from the China Health and Retirement Longitudinal Study (CHARLS). The study collected patient information on their demographic characteristics, socioeconomic status, other health-related behavior, and history of musculoskeletal pain and hip fractures. Univariate and multivariate analyses were conducted to investigate the factors influencing the risk of hip fracture, including factors related to the individual and to musculoskeletal pain. P for trend test was performed to assess the trend of each continuous variable. The robustness and bias were assessed using the bootstrap method. Restricted cubic spline regression was utilized to identify linear or non-linear relationships. RESULTS: Among the 18,813 respondents, a total of 215 individuals reported that they have experienced a hip fracture. An increased risk of hip fracture was associated with the presence of waist pain and leg pain (P < 0.05), as well as with an increased number of musculoskeletal pain sites (P < 0.05). For individuals aged 65 and above, a significant association was found between age and the risk of hip fracture (P < 0.05). Furthermore, respondents with lower education level had a higher risk of hip fracture compared to those with higher education levels (P < 0.05). CONCLUSION: In the Chinese population, the risk of hip fracture was found to be associated with both the location and extent of musculoskeletal pain, as well as with other factors such as age and demographic characteristics. The findings of this study may be useful for informing policy development and treatment strategies, and provide evidence for comparison with data from other demographic populations.

Failure modes after anterior cruciate ligament reconstruction: a systematic review and meta-analysis.

PURPOSE: The reason for graft failure after anterior cruciate ligament reconstruction (ACLR) is multifactorial. Controversies remain regarding the predominant factor and incidence of failure aetiology in the literature. This review aimed to provide a meta-analysis of the literature to evaluate the relative proportion of various failure modes among patients with ACLR failure. METHODS: The PubMed, Embase, Cochrane Library, Web of Science, and EBSCO databases were searched for literature on ACLR failure or revision from 1975 to 2021. Data related to causes for ACLR surgical failure were extracted, and a random effects model was used to pool the results, which incorporates potential heterogeneity. Failure modes were compared between different populations, research methods, graft types, femoral portal techniques, and fixation methods by subgroup analysis or linear regression. Funnel plots were used to identify publication bias and small-study effects. RESULTS: A total of 39 studies were analyzed, including 33 cohort studies and six registry-based studies reporting 6578 failures. The results showed that among patients with ACLR failure or revision, traumatic reinjury was the most common failure mode with a rate of 40% (95% CI: 35-44%), followed by technical error (34%, 95% CI: 28-42%) and biological failure (11%, 95% CI: 7-15%). Femoral tunnel malposition was the most common cause of the technical error (29%, 95% CI: 18-41%), with more than two times higher occurrence than tibial tunnel malposition (11%, 95% CI: 6-16%). Traumatic reinjury was the most common factor for ACLR failure in European populations and in recent studies, while technical errors were more common in Asian populations, earlier studies, and surgery performed using the transtibial (TT) portal technique. Biological factors were more likely to result in ACLR failure in hamstring (HT) autografts compared to bone-patellar tendon-bone (BPTB) autografts. CONCLUSION: Trauma is the most important factor leading to surgical failure or revision following ACLR. Technical error is also an important contributing factor, with femoral tunnel malposition being the leading cause of error resulting in failure.

A 59-Electron Non-Magic-Number Gold Nanocluster Au99(C≡CR)40 Showing Unexpectedly High Stability.

An atomically resolved gold nanocluster Au99(C≡CC6H3-2,4-F2)40 (Au99) with an unusual 59 valence electrons has been synthesized. Single-crystal X-ray diffraction reveals that its Au79 kernel is a Au49 Marks decahedron capped by two Au15 units. The surface structure of Au99 consists of 20 linear Au(C≡CR)2 staples. Intercluster interactions are observed between these D5 symmetric clusters. The existence of an unpaired electron is verified by magnetic measurement. Interestingly, this open-shell gold cluster Au99 stays intact in toluene solution at 80 °C for more than a week, and it has good charging-discharging capability under electrochemical conditions. The compact ligand shell protection around the symmetric core accounts for the high stability. This work suggests that geometric factors may play a crucial role in determining the stability of a metal nanocluster, even though the cluster has an open-shell electronic structure.

Bottom-up Synthesis of Water-Soluble Gold Nanoparticles Stabilized by N-Heterocyclic Carbenes: From Structural Characterization to Applications.

N-heterocyclic carbenes (NHCs) have become attractive ligands for functionalizing gold nanoparticle surfaces with applications ranging from catalysis to biomedicine. Despite their great potential, NHC stabilized gold colloids (NHC@AuNPs) are still scarcely explored and further efforts should be conducted to improve their design and functionalization. Here, the 'bottom-up' synthesis of two water-soluble gold nanoparticles (AuNP-1 and AuNP-2) stabilized by hydrophilic mono- and bidentate NHC ligands is reported together with their characterization by various spectroscopic and analytical methods. The NPs showed key differences likely to be due to the selected NHC ligand systems. Transmission electron microscopy (TEM) images showed small quasi-spherical and faceted NHC@AuNPs of similar particle size (ca. 2.3-2.6 nm) and narrow particle size distribution, but the colloids featured different ratios of Au(I)/Au(0) by X-ray photoelectron spectroscopy (XPS). Furthermore, the NHC@AuNPs were supported on titania and fully characterized. The new NPs were studied for their catalytic activity towards the reduction of nitrophenol substrates, the reduction of resazurin and for their photothermal efficiency. Initial results on their application in photothermal therapy (PTT) were obtained in human cancer cells in vitro. The aforementioned reactions represent important model reactions towards wastewater remediation, bioorthogonal transformations and cancer treatment.

Structural Engineering toward Gold Nanocluster Catalysis.

Atomically precise gold nanoclusters provide great opportunities to explore the relationship between the structure and properties of nanogold catalysts. A nanocluster consists of a metal core and a surface ligand shell, and both the core and shell have significant effects on the catalytic properties. Thanks to their precise structures, the active metal site of the clusters can be readily identified and the effects of ligands on catalysis can be disclosed. In this Minireview, we summarize recent advances in catalytic research of gold nanoclusters, emphasizing four strategies for constructing open metal sites, including by post-treatment, the bulky ligands strategy, the surface geometric mismatch method, and heteroatom doping procedures. We also discuss the effects of ligands on the catalytic activity, selectivity, and stability of gold cluster catalysts. Finally, we present future challenges relating to gold cluster catalysis.

Anion-Directed Regulation of Structures and Luminescence of Heterometallic Clusters.

Anions have been used to regulate the structures and luminescence of heterometallic clusters. Introducing ClO4 - into orange-emissive, butterfly-like [(C)(Au-PPhpy2 )6 Ag4 ](BF4 )6 (1, PPhpy2 =bis(2-pyridyl)phenylphosphine) leads to the formation of red-emissive [(C)(Au-PPhpy2 )6 Ag5 (ClO4 )3 ](ClO4 )4 (2) with a novel trigonal bipyramidal structure; employing PhCO2 - gives yellow-emissive, hexagram-like [(C)(Au-PPhpy2 )6 Ag6 (PhCO2 )3 ](BF4 )5 (3). Notably, 1 exhibits weak luminescence in CH2 Cl2 /CH3 OH=1 : 1 (v : v) with a quantum yield (QY) of 0.05, whereas it was dramatically increased to 0.49 and 0.83 for 2 and 3, respectively. Theoretical calculation confirms that the involvement of anions in the electronic structures is responsible for the shifts of emission. The high QYs of 2 and 3 are attributed to the protection provided by ligands and anions. This work demonstrates that anions may serve as an extra designable factor beyond just counterions for functional metal clusters.

Ligand Engineering toward the Trade-Off between Stability and Activity in Cluster Catalysis.

We report the structures, stability and catalysis properties of two Ag21 nanoclusters, namely [Ag21 (H2 BTCA)3 (O2 PPh2 )6 ]SbF6 (1) and [Ag21 (C≡CC6 H3 -3,5-R2 )6 (O2 PPh2 )10 ]SbF6 (2) (H4 BTCA=p-tert-butylthiacalix[4]arene, R=OMe). Both Ag21 structures possess an identical icosahedral kernel that is surrounded by eight peripheral Ag atoms. Single-crystal structural analysis and ESI-MS revealed that 1 is an 8-electron cluster and 2 has four free electrons. Theoretical results show that the P-symmetry orbitals are found as HOMO-1 and HOMO states in 1, and the frontier unoccupied molecular orbitals (LUMO, LUMO+1 and LUMO+2) show D-character, indicating 1 is a superatomic cluster with an electronically closed shell 1S2 1P6 , while 2 has an incomplete shell configuration 1S2 1P2 . These two Ag21 clusters show superior stability under ambient conditions, and 1 is robust even at 90 °C in toluene and under oxidative conditions (30 % H2 O2 ). Significantly, 2 exhibits much higher activity than 1 as catalyst in the reduction of 4-nitrophenol. This work demonstrates that ligands can influence the electronic structures of silver clusters, and further affect their stability and catalytic performance.

Molecular Gold Nanocluster Au156 Showing Metallic Electron Dynamics.

The boundary between molecular and metallic gold nanoclusters is of special interest. The difficulty in obtaining atomically precise nanoclusters larger than 2 nm limits the determination of such a boundary. The synthesis and total structural determination of the largest all-alkynyl-protected gold nanocluster (Ph4P)6[Au156(C≡CR)60] (R = 4-CF3C6H4-) (Au156) are reported. It presents an ideal platform for studying the relationship between the structure and the metallic nature. Au156 has a rod shape with the length and width of the kernel being 2.38 and 2.04 nm, respectively. The cluster contains a concentric Au126 core structure (Au46@Au50@Au30) protected by 30 linear RC≡C-Au-C≡CR staple motifs. It is interesting that Au156 displays multiple excitonic peaks in the steady-state absorption spectrum (molecular) and pump-power-dependent excited-state dynamics as revealed in the transient absorption spectrum (metallic), which indicates that Au156 is a critical crossover cluster for the transition from molecular to metallic state. Au156 is the smallest-sized gold nanocluster showing metal-like electron dynamics, and it is recognized that the cluster shape is one of the important factors determining the molecular or metallic nature of a gold nanocluster.

Interference screws are more likely to perform better than cortical button and cross-pin fixation for hamstring autograft in ACL reconstruction: a Bayesian network meta-analysis.

PURPOSE: Anterior cruciate ligament (ACL) reconstruction is widely accepted as the first choice of treatment for ACL injury, but there is disagreement in the literature regarding the optimal femoral fixation method. This meta-analysis assesses the evidence surrounding three common femoral fixation methods: cortical button (CB), cross-pin (CP) and interference screws (IS). METHODS: A systematic search was conducted in Medline, EMBASE and the Cochrane Library to identify studies with evidence level I or II that compared at least two femoral fixation methods with hamstring autograft for ACL reconstruction. Ten primary outcomes were collected. Risk of bias was assessed following the Cochrane Handbook for Systematic Reviews of Interventions. Standardized mean differences (SMD) were estimated using random-effects network meta-analysis in a Bayesian framework. Probability of ranking best (ProBest) and surface under the cumulative ranking curve (SUCRA) were used to rank all treatments. Funnel plots were used to identify publication bias and small-study effects. RESULTS: Sixteen clinical trials were included for analysis out of 2536 retrieved studies. Bayesian network meta-analysis showed no significant differences among the three fixation methods for the ten primary outcome measures. Based on the 10 outcome measures, the IS, CB and CP had the highest ProBest in 5, 5 and 0 outcomes, and the highest SUCRA values in 5, 4 and 1 outcomes, respectively. No substantial inconsistency between direct and indirect evidence, or publication bias was detected in the outcomes. CONCLUSION: There were no statistical differences in performance among the CP, CB and IS femoral fixation methods with hamstring autograft in ACL reconstruction, although the IS was more likely to perform better than CB and CP based on the analysis of outcome measures from the included studies. LEVEL OF EVIDENCE: 1.

Extracellular Vesicles from Mesenchymal Stromal Cells for the Treatment of Inflammation-Related Conditions.

Over the past two decades, mesenchymal stromal cells (MSCs) have demonstrated great potential in the treatment of inflammation-related conditions. Numerous early stage clinical trials have suggested that this treatment strategy has potential to lead to significant improvements in clinical outcomes. While promising, there remain substantial regulatory hurdles, safety concerns, and logistical issues that need to be addressed before cell-based treatments can have widespread clinical impact. These drawbacks, along with research aimed at elucidating the mechanisms by which MSCs exert their therapeutic effects, have inspired the development of extracellular vesicles (EVs) as anti-inflammatory therapeutic agents. The use of MSC-derived EVs for treating inflammation-related conditions has shown therapeutic potential in both in vitro and small animal studies. This review will explore the current research landscape pertaining to the use of MSC-derived EVs as anti-inflammatory and pro-regenerative agents in a range of inflammation-related conditions: osteoarthritis, rheumatoid arthritis, Alzheimer's disease, cardiovascular disease, and preeclampsia. Along with this, the mechanisms by which MSC-derived EVs exert their beneficial effects on the damaged or degenerative tissues will be reviewed, giving insight into their therapeutic potential. Challenges and future perspectives on the use of MSC-derived EVs for the treatment of inflammation-related conditions will be discussed.

Clinical-Grade Human Embryonic Stem Cell-Derived Mesenchymal Stromal Cells Ameliorate the Progression of Osteoarthritis in a Rat Model.

Mesenchymalstem cell (MSC)-based therapy is being increasingly explored in preclinical and clinical studies as a regenerative method for treating osteoarthritis (OA). However, the use of primary MSCs is hampered by a number of limitations, including donor heterogeneity and inconsistent cell quality. Here, we tested the therapeutic potential of embryonic stem cell-derived MSCs (ES-MSCs) in anOA rat model. ES-MSCs were generated and identified by morphology, trilineage differentiation and flow cytometry. Sprague Dawley rats were treated with either a single dose (106 cells/rat) of ES-MSCs or with three doses spaced one week apart for each dose, starting at four weeks after anterior cruciate ligament transectionto induce OA. Cartilage quality was evaluated at 6 and 10 weeks after treatment with behavioral analysis, macroscopic examination, and histology. At sixweeks after treatment, the groups treated with both single and repeated doses of ES-MSCs had significantly better modified Mankin scores and International Cartilage Repair Society (ICRS) macroscopic scores in the femoral condyle compared to the control group. At 10 weeks after treatment, the repeated doses group had a significantly better ICRS macroscopic scores in the femoral condyle compared to the single dose and control groups. Histological analysis also showed more proteoglycan and less cartilage loss, along with lower Mankin scores in the repeated doses group. In conclusion, treatment with multiple injections of ES-MSCs can ameliorate OA in a rat model. TheES-MSCs have potential to be considered as a regenerative therapy for OA, and can provide an infinite cellular source.

Enriching Structural Diversity of Alkynyl-Protected Gold Nanoclusters with Chlorides.

The synthesis and isolation of alkynyl/chloride-protected gold nanoclusters is described. Silica gel column chromatography is effective in isolating gold nanoclusters from the as-synthesized cluster mixture to give the clusters Na[Au25 L18 ] (Au25 ), [HNEt3 ]3 [Au67 L32 Cl4 ] (Au67 ), [HNEt3 ]4 [Au106 L40 Cl12 ] (Au106 ), L=3,5-bis(trifluoromethyl)-phenylacetylide. Au67 and Au106 are new clusters; the structures were determined by X-ray single-crystal diffraction. Au67 contains a distorted Au18 Marks decahedron shelled by an irregular Au32 and further protected with two V-shaped Au2 L3 , 13 linear AuL2 staples and 4 chlorides. Au67 is the first structurally determined 34e superatomic gold nanocluster. Au106 is composed of 106 Au atoms co-protected by alkynyls and chlorides. It has a Au79 kernel, like in Au102 (p-MBA)44 . The surface structure of Au106 includes 20 linear Au-alkynyl staples, 5 Cl-Au-Cl and 2 Cl-Au motifs. These three gold nanoclusters show size-dependent electrochemical properties.

Cluster From Cluster: A Quantitative Approach to Magic Gold Nanoclusters [Au25 (SR)18 ].

High-yield and large-scale synthesis are highly demanded for the studies of gold nanoclusters. We developed a "cluster from cluster" approach to assemble gold nanoclusters with preformed atomically precise Au13 precursors. This facile approach has proved to be very effective in the synthesis of the well-known magic cluster [Au25 (SR)18 ]- , which could prepare the target cluster in high yield (overall yield up to ≈100 %) at large scale (gram-scale based on gold). This method can be applied in the synthesis of 10 Au25 clusters with different R groups. This work presents an important approach that may be extended to high-yield and large-scale synthesis of other metal nanoclusters.

Efficacy and safety of COVID-19 vaccines: a systematic review.

OBJECTIVE: To evaluate systematically the efficacy and safety of COVID-19 vaccines. METHODS: PubMed, Embase, Cochrane Library, Clinicaltrial.gov, CNKI, Wanfang Data, China Biomedical Literature Service System, and China Clinical Trial Registry were searched for randomized controlled trials of COVID-19 vaccines published up to December 31, 2020. The Cochrane bias risk assessment tool was used to assess the quality of studies. A qualitative analysis was performed on the results of clinical trials. RESULTS: Thirteen randomized, blinded, controlled trials, which involved the safety and efficacy of 11 COVID-19 vaccines, were included. In 10 studies, the 28-day seroconversion rate of subjects exceeded 80%. In two 10 000-scale clinical trials, the vaccines were effective in 95% and 70.4% of the subjects, respectively. The seroconversion rate was lower than 60% in only one study. In six studies, the proportion of subjects who had an adverse reaction within 28 days after vaccination was lower than 30%. This proportion was 30%-50% in two studies and > 50% in the other two studies. Most of the adverse reactions were mild to moderate and resolved within 24 hours after vaccination. The most common local adverse reaction was pain or tenderness at the injection site, and the most common systemic adverse reaction was fatigue, fever, or bodily pain. The immune response and incidence of adverse reactions to the vaccines were positively correlated with the dose given to the subjects. The immune response to the vaccines was worse in the elderly than in the younger population. In 6 studies that compared single-dose and double-dose vaccination, 4 studies showed that double-dose vaccination produced a stronger immune response than single-dose vaccination. CONCLUSIONS: Most of the COVID-19 vaccines appear to be effective and safe. Double-dose vaccination is recommended. However, more research is needed to investigate the long-term efficacy and safety of the vaccines and the influence of dose, age, and production process on the protective efficacy.

Isomerization in Alkynyl-Protected Gold Nanoclusters.

We report the controlled synthesis and structures of two isomeric gold nanoclusters, whose compositions are determined to be Au23(C≡CBut)15 (denoted as Au23-1 and Au23-2) by single-crystal X-ray diffraction and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. This is the first time isomerism is discovered in alkynyl-protected gold nanoclusters. The metal-to-ligand ratios in these two clusters are different from known Aun(SR)m systems and have not been observed in the Aux(C≡CPh)y family. This pair of isomers exhibits different optical properties, although they have similar structures and identical components. For both Au23 clusters, time-dependent density functional theory calculations revealed the frontier orbitals highest occupied molecular orbital (HOMO)-1, HOMO, and lowest unoccupied molecular orbital (LUMO) are mainly constructed from the Au15 kernel and V-shaped alkynyl-gold motifs. The HOMO → LUMO transition of Au23-1 is optically forbidden, whereas it is allowed in Au23-2. It is also found that Au23-2 cluster can be transformed to Au23-1 spontaneously under ambient conditions. This work offers further insight into the synthesis and isomerism of all-alkynyl-protected gold nanoclusters and will stimulate more investigation of isomeric metal nanoclusters.

Large autologous ilium with periosteum for tibiotalar joint reconstruction in Rüedi-Allgöwer III or AO/OTA type C3 pilon fractures: a pilot study.

BACKGROUND: Management of Rüedi-Allgöwer III or AO/OTA type C3 pilon fracture presents numerous challenges to the orthopaedic surgeon. A joint preservation technique using a large autologous ilium with periosteum in combination with internal implant fixation was reported to improve the outcome of reconstruction. METHODS: Twenty-five patients according to Tscherne/Oestern FxCO-I closed fracture and FxOI open fractures classification after Rüedi-Allgöwer III or AO/OTA type C3 pilon fracture received a large autologous ilium with periosteum for tibiotalar joint reconstruction and open reduction and internal fixation (ORIF), between March 2015 and September 2018. The visual analog scale (VAS), American Orthopaedic Foot & Ankle Society (AOFAS) score, and Burwell and Charnley criteria were used for outcome analysis. RESULTS: Twenty patients with an average age of 45.2 years were followed for an average of 18.3 months. The VAS and AOFAS scores, and Burwell and Charnley ratings were recorded at the last follow-up after reconstructive surgery. Two patients developed redness and swelling at the wound site, but recovered after local care and dressing changes. No patient displayed deep surgical site infection, donor site complication, non-union or local complication during the final follow-up. The average bone union time was 18.3 months (range 3-36). CONCLUSIONS: Large autologous ilium with periosteum in combination with ORIF can be performed for tibiotalar joint reconstruction. This experimental procedure reduces the risk of post-operative complications following articular reconstruction for Rüedi-Allgöwer III or AO/OTA type C3 pilon fractures in short follow-up. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

[Bushen Huoxue Recipe reduces cyclophosphamide-induced apoptosis of spermatogenic cells in mice].

OBJECTIVE: To investigate the effect of Bushen Huoxue Recipe (BHR) on cyclophosphamide-induced apoptosis of testicular spermatogenic cells in mice and its possible action mechanisms. METHODS: Fifty male Babl/c mice aged 8－9 weeks were randomly divided into five groups of an equal number: blank control, model control, low-dose BHR, medium-dose BHR and high-dose BHR. The animals in the blank control group were intraperitoneally injected with normal saline, while those in the other four groups with cyclophosphamide at 50 mg/kg/d, all for 7 days. After modeling, the mice in the blank and model control groups were given distilled water via gavage once a day, and those in the low-, medium- and high-dose BHR groups treated intragastrically with BHR at 7.5, 15 and 30 g/kg/d qd for 30 successive days. Then, the apoptosis index of the testicular spermatogenic cells was obtained by TUNEL and the expressions of Bax and Bcl-2 mRNA and proteins determined by RT-PCR and Western blot, respectively. RESULTS: Compared with the mice in the blank control group, the BHR model controls showed dramatically increased apoptosis of testicular spermatogenic cells and up-regulated mRNA and protein expressions of Bax and Bcl-2 in the testis tissue (P < 0.01). In comparison with the model controls, the mice in the BHR treatment groups exhibited significantly reduced apoptosis of testicular spermatogenic cells and down-regulated mRNA and protein expressions of Bax and Bcl-2 in the testis tissue (P < 0.01). CONCLUSIONS: Bushen Huoxue Recipe can reduce cyclophosphamide-induced apoptosis of testicular spermatogenic cells in mice, which may be associated with its ability of regulating the expressions of Bax and Bcl-2 mRNA and proteins in the testis tissue.

Formation of an Alkynyl-Protected Ag112 Silver Nanocluster as Promoted by Chloride Released In Situ from CH2 Cl2.

By directly reducing alkynyl-silver precursors, we successfully obtained a large alkynyl-protected silver nanocluster, (C7 H17 ClN)3 [Ag112 Cl6 (C≡CAr)51 ], which is hitherto the largest structurally characterized silver nanocluster in the alkynyl family. The cluster exhibits four concentric core-shell structures (Ag13 @Ag42 @Ag48 @Ag9 ), and four types of alkynyl-silver binding modes are observed. Chloride was found to be critical for the stabilization and formation of the silver nanocluster. The release of chloride ions in situ from CH2 Cl2 solvent has been confirmed by mass spectrometry. This study suggests that the combination of alkynyl and halide ligands will pave a new way for the synthesis of large silver nanoclusters.

Structure Determination of Alkynyl-Protected Gold Nanocluster Au22 (t BuC≡C)18 and Its Thermochromic Luminescence.

An alkynyl-protected gold nanocluster, Au22 (t BuC≡C)18 (1), has been synthesized and its structure has been determined by single-crystal X-ray diffraction. The molecular structure consists of a Au13 cuboctahedron kernel and three [Au3 (t BuC≡C)4 ] trimeric staples. The cluster 1 has strong luminescence in the solid state with a 15 % quantum yield, and it displays interesting thermochromic luminescence as revealed by temperature-dependent emission spectra. The enhanced room-temperature emission is characterized as thermally activated delayed fluorescence.